/*
 * Copyright (c) 2011 Imre Fazekas.
 * All rights reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * Neither the name of the Brillien nor the names of its
 * terms and concepts may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package com.vii.streamline.jsonrpc;

import com.vii.streamline.CommServlet;
import com.vii.streamline.json.JsonRpcError;
import com.vii.streamline.json.JsonRpcListener;
import com.vii.streamline.services.error.StreamLineException;
import com.vii.streamline.web.HttpServices;
import org.apache.http.HttpStatus;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Abstract Servlet class representing a dispatcher providing a JSON-RPC 2.0-based interface delegating all incoming calls to the internal business logic.
 */
public abstract class JsonRpcDispatcherServlet extends CommServlet {

    protected JsonRpcListener       listener;

    /**
     * Returns a new instance of a {@link JsonRpcListener} implementation.
     */
    protected abstract JsonRpcListener getJsonRpcListener( ) throws ServletException;


    @Override
    protected void sendError( HttpServletRequest req, HttpServletResponse resp, int errorCode, String errorMessage, Object errorValue){
        sendError( req, resp, new JsonRpcError( errorCode, errorMessage, errorValue ) );
    }

    @Override
    protected void sendError( HttpServletRequest req, HttpServletResponse resp, JsonRpcError error){
        try {
            if( logger != null )
                logger.debug( "Sending error message:" + error );
            resp.setStatus( HttpStatus.SC_BAD_REQUEST );
            HttpServices.sendJSONMessage(req, resp, error.wrapResponse() );
        } catch (StreamLineException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void doInnerPost(HttpServletRequest req, HttpServletResponse resp) throws StreamLineException{
        String requestString = HttpServices.getRequestBody(req);

        if( logger != null )
            logger.debug( "Received HTTP-Post body:" + requestString );

        Object response = listener.process( requestString );

        if( response != null )
            sendResponse( req, resp, response );
    }


}
